Hydraulic driving apparatus



Jan. 5, 1960 l. SUBLETT ETAL 2,919,678

HYDRAULIC DRIVING APPARATUS Filed Aug. 13, 1957 3 Sheets-Sheet 1 & as

f/yaenuua Pzcssuze Sam: c E

INVENTORS Jan. 5, 1960 l. SUBLETT ETAL 2,919,678

HYDRAULIC DRIVING APPARATUS Filed Aug. 15, 1957 3 Sheets-Sheet 3 UnitedStates Patent HYDRAULIC DRIVING APPARATUS Ira Suhlett and Charles D.Johnson, Fairmont, Minn., assignors to Fairmont Railway Motors,Incorporated, Fairmont, Minn., a corporation of Minnesota ApplicationAugust 13, 1957, Serial No. 677,902

12 Claims. (Cl. 121-25) This invention relates to a hydraulic drivingapparatus and, more particularly, to an improvement of the apparatusdisclosed in United States Patent No. 2,731,796.

In apparatus of this type it has been found that a real problem ofmaintenance exists in instances where the apparatus, in the course ofits operation, is sub ected to an excessive amount of 'shock and wear,such as in the case when it is used as a spike driver or paving breaker.

Thus, it is one of the objects of this invention to provide an improvedapparatus wherein the problem of maintenance, involving replacement andadjustment of parts thereof, is materially reduced.

It is a further object of this invention to provide an improvedapparatus which is simple and compact in construction, eflicient inoperation, and is capable of being utilized in a variety of differentways.

Further and additional objects will appear from the description,accompanying drawings, and appended claims.

In accordance with one embodiment of this invention, an improved drivingapparatus is provided comprising a source of hydraulic pressure, areservoir for hydraulic fluid, and a housing provided with an elongatedchamber. The chamber is divided into first and second compartments by anapertured partition. The first chamber is in continuous communicationwith the source of hydraulic pressure. Slidably mounted within theaperture of the partition is an elongated reciprocating element which isadapted to efiect isolating of one compartment from the other.Cooperating with said housing chamber and operatively connected to thesource, the second compartment, and the reservoir, is an adjustable unitfor controlling the direction of movement of said element within saidchamber. The control unit, when in one position of adjustment,interconnects the source andthe second compartment whereby thereciprocating element is actu ated in a direction toward one end of thechamber and, when in a second position of adjustment, interconnects thereservoir and the second compartment whereby the reciprocating elementis actuated in a direction toward the opposite end of the chamber.

For a more complete understanding of this invention, reference should bemade to the drawings, wherein:

Figure 1 is a right side elevational view of the apparatus shown in Fig.2.

Fig. 2 is a vertical sectional view taken along line 2-2 of Fig. 1 andwith the reciprocating element shown in its uppermost position withrespect to the housing.

'Fig. 3 is similar to Fig. 2, but showing the reciprocating element inits lowermost position with respect to the housing.

Fig. 4 is an enlarged fragmentary sectional view taken along line 44 ofFig. 5.

Fig. 5 is a top plan view of Fig. 2.

Fig. 6 is a sectional view taken along'line 66 of Fig. 4.

Fig. 7 is an enlarged fragmentary sectional view taken along line 77 ofFig. 3.

Fig. 8 is a sectional view taken along line 8-8 of Fig. 7.

Fig. 9 is an enlarged fragmentary sectional view taken along line 99 ofFig. 4.

Referring now to the drawings, a hydraulic driving apparatus is shownwhich is an improvement over the apparatus described in Patent No.2,731,796. The apparatus is adapted for a wide variety of uses, such asa spike driver, spike puller, paving breaker, or the like, wherein areciprocatory movement may be employed to impart a driving force.

The apparatus 10 is shown as applied to a spike driver; however, it isto be understood, of course, that this is done merely by way of exampleand the invention is not in-. tended to be limited to this particularapplication.

The apparatus 10 comprises an elongated housing 11 which, in thisinstance, is formed into at least three sections: a central section 11a;a top section 11b, which is secured by any suitable means, such as bolts12, to the upper end of central section 11a; and a lower section 110,which is also secured by means of bolts 12 to the lower end of section11a. Housing section 11a is provided with an elongated chamber 13, inwhich is disposed a stationary apertured unit 14 which is adapted toeflfect division of chamber 13 into two aligned compartments 13a and1312. Upper housing section 11b is also provided with an elongatedchamber 15 which is coaxially disposed and communicates with compartment13b of the central housing section 11a. Apertured unit 14, in thisinstance, is shown as comprising a pair of axially spaced bearingelements 14a and 14b, which are disposed in fixed relation withinsection chamber 13. Both elements are provided with central openings14:: which are in coincident relation with respect to one another. Bothopenings communicate at one end with the space 14d between the elements.Space 14d communicates with a port 16 formed in housing section 11a, fora purpose to be hereinafter discussed. Housing section 11a is providedwith a second port 17 communicating with compartment 13b which isadjacent to chamber 15 of housing section 11b, as shown more clearly inFig. 2.

Port 17 functions as a connection ment 13b, section chamber 15, andhydraulic pressure accumulator 18, the latter being secured to housingsection 11b by means of a suitable bracket 18a. Also formed in housingsection chambers 13b and 15 is a port 20, which serves to connectcompartment 13b with an elongated passageway 21, see Fig. 4, formed insection 11a and disposed substantially parallel to chamber 13.Passageway 21 is in continuous communication with a source of hydraulicpressure, and thus, a positive hydraulic pressure is maintained at alltimes in compartment plenish the hydraulic pressure spent by theaccumulator 18 during certain periods of operation of the apparatus, aswill be more clearly described hereinafter.

.Port 16, which has previously been mentioned as being formed in theupper portion of housing section 11a, see Fig. 2, communicates with aconduit 22, which serves to between compartconnect port 16 with acontrol unit 23, the latter to be described more fully hereinafter ascontrolling the direction of movement of a plunger 14.

Plunger 14 is mounted within the housing 11 for reciprocatory movementwith instance, is formed of a plurality of independent aligned sections24a, 24b, and 24c. Plunger 24 serves, in this instance, to impart ahammering blow on a spike 25, for the purpose of driving the latter intoa suitable tie or the like (not shown).

11a and communicating with- 13b and is adapted to re-' respect theretoand, in this The bottom section 24a of plunger 3 24 is disposed in thelower housing section 110 and contacts directly the head of the spike25. The lower end of housing section lie is open to accommodate the headof the spike. The housing section He is also provided with an axiallyextending annular pocket 27 formed in the interior surface of thesection and in which is disposed for slidab'le movement with respectthereto, a shoulder 26 provided on plunger section 24a. The axial lengthof pocket 27 determines the extent to which the plunger section 24a iscapable of moving relative to the housing section interior.

Plunger section 24b is the central section and is completely disposedwithin housing section 11a. The upper end of plunger section 24b isprovided with an enlarged head 28 which is adapted to slidably contactthe compartment wall 13a. The remaining depending portion of plungersection 24b is reduced in diameter, as shown in Figs. 2 and 3. Thedepending portion of plunger section 24b is embraced by a seating sleeve29, which serves a dual function, namely, to prevent leakage of thehydraulic fluid through the bottom of compartment 13a and, also, tofunction as a bearing guide for the plunger section 24!). Communicatingwith the lower end of compartment 13a is a passageway 30 formed inhousing section 11a which, in turn, is in communication with apassageway 31, the latter being formed in the housing 23a of controlunit 23. Unit 23 will be described more fully hereinafter.

Plunger section 240 is the upper section and is in continuous abuttingengagement with the head 28 of plunger section 241;. Section 24c is of asmaller diameter than head 28, as seen in Figs. 2 and 3. Plunger section24: is slidably disposed within the coincident openings 14-0 of bearingelements 14a and 14b and is adapted to effect isolation between chambers13a and 13b. Plunger section 240 has the lower end 32 thereof providedwith a plurality of symmetrically arranged axially extending splines ofequal length. The upper or opposite end 33 of section 240 is alsoprovided with a plurality of symmetrically arranged, axially extendingsplines which are of equal length but of a length considerably greaterthan the length of the first mentioned splines.

Upon plunger 24c reaching the uppermost terminus of its reciprocatingmotion, as shown in Fig. 2, the grooves formed in splined end 32cooperate with the perimeter of openings 14c of element 14b and effectscommunication between space 14a formed between bearing elements 14a and14b and compartment 13a formed in housing section 11a. When, however,the plunger section 24: is at the lowermost terminus of reciprocatingmovement, as shown more clearly in Fig. 3, the grooves formed in splinedend 33 cooperate with the perimeter of opening 140 in element 14a andeffects communication between compartment 13b and space Md. The effectof these alternate communications with space 14d is to automaticallyproduce change in direction of movement of the plunger 14.

Control unit 23, as shown in Fig. 2, is provided with housing 23::having formed therein a central elongated cavity 34, a first portcommunicating with cavity 34 and connected by suitable conduit 35a to asource of hydraulic pressure, and a second port 36 communicating withcavity 34 and spaced, in this instance, beneath port 35 and connected bysuitable conduit 36a to a reservoir for hydraulic fluid. Housing 23a isalso provided with a passageway, not shown, which connects first port 35with the lower end of passageway 21 formed in house section 11a, andthus, as heretofore mentioned, there is continuous communication betweenpassageway 21 and the source of hydraulic pressure.

Mounted for reciprocatory movement within elongated cavity 34 is a spool37 which is biased by a coil spring 38 to assume a normal upwardlydisposed position, as shown more clearly in Fig. 2. The spool 37 isprovided with a plurality of relatively spaced shoulders which coactwith the annular protuberances formed in the contour of cavity 34 andeffect either communication of port 35 with passageway 31 orcommunication of port 36 with passageway 31. The upper end of cavity 34terminates in a restricted passageway 39 which, in turn, is incommunication with conduit 22. Thus, the function of port 16 in housingsection 11a, conduit 22, and restricted passageway 39 is to permit highpressure hydraulic fluid to react on a small piston 37 which, in turn,engages the upper end of spool 37, when the plunger sectlon 240 is inits lowermost terminus, and effect overcoming of upward biasing forceexerted by spring 38 on spool 37 and thereby cause downward movement ofspool 37 until there is interconnection between port 35 and passageway31. Upon this interconnection being established, the high pressurehydraulic fluid reacts on the underside of head 23 formed on plungersection 24b, and cause the latter to move in an upward direction withinhousing section chamber 13a. The diameter of head 2%, as compared to thediameter of the upper end of plunger section 240, is such that theresultant force exerted by the hydraulic fluid on the head 23 in anupward direction is greater than the resultant force exerted on theupper end of plunger section 24c. The differential between theseresultant forces determines the speed ith which the plunger will moveupwardly.

Upon plunger reaching its uppermost terminus, splined end 32 of plungersection 24c effects communication between port 16 and compartment 130,whereupon the high pressure hydraulic fluid contained within port 16,conduit 22, and restricted passageway 39 is discharged into thereservoir through an eiongated cavity it), formed in housing section11a, in spaced parallel relation with chamber 13 and passageway 21, asseen more clearly in Fig. 4. Cavity 4t] communicates directly with thereservoir through the conduit 36. As soon as this communication iseffected by splined end 32, the force of coil spring 38 is sufficient tomove the spool 37 and abutting piston 37 to their uppermost positions,as shown in Pig. 2, at which time the compartment 13a disposed to theunderside of head 28 of plunger section 24b is vented to the reservoirthrough passageways 31, 34, 36, and conduit 36a, thereby permitting thehydraulic pressure exerted on the upper end 33 of plunger section 240 tocause the plunger to be swiftly moved in a downward direction relativeto the housing 11 into striking engagement with plunger section 24a.

Formed in housing 23a for control unit 23 is a small bypass 41, seeFigs. 2 and 3, which has one end thereof terminating in passageway 39and the other end thereof terminating in passageway 31. Disposedintermediate the ends of by-pass 41 is a restrictor piece 42. Thefunction of bypass 41 and piece 42 is to replace any leakage which mi htoccur past piston 37 and spool 37 and thus insure that spool 37 piston37 remain in their down position within the housing 23a until thesplined end 33 of the plunger 24- uncovers port 16 to the reservoir,whereupon spool 37 and piston 37' are moved upwardly under the force ofspring 38.

In order to effectively dissipate heat which might be created duringreciprocatory movement of the plunger 24 in housing 11, a plurality ofcooling fins 43 are formed on the outer periphery of housing section11a. It is to be understood, of course, that if desired, the housingsection 11a may be water-jacketed for cooling instead.

The advantages of having separate plunger sections 241; and 24c, ratherthan an integral construction, is that it facilitates manufacture of theplunger itself and, in addition, enables one section of the plunger tobe readily replaced in case of wear or damage. In addition, any inherentstructural weaknesses which might be created in an integral plunger havebeen avoided. Furthermore, the splined ends 32 and 33 of the uppersection 24c are of sufficient lengths as to permit the plunger sectionto be disposed at all times in the coincident openings 14c formed in.bearingelements 14a and 1412, when the plunger is at its terminalpositions and, thus, insures proper alignment betwen the bearingelements and the plunger.

The apparatus may be rendered operative or inoperative by a suitableon-ofi control, not shown, incorporated in conduit 35a leading from theapparatus to the source of hydraulic pressure. The apparatus is ofcompact, relatively light-weight, construction and may be readilymounted. on a suitable support, if desired, or may be provided withsuitable handles to enable the operator to readily manipulate theapparatus.

Thus, it will be seen that an improved hydraulic driving apparatus hasbeen provided which is of sturdy, yet simple, construction, fullyautomatic in operation, and may be readily adapted for a variety ofuses.

'While a particular embodiment of this invention has been shown, it willbe understood, of course, that main" vention is not to be limitedthereto, since many modifications may be made, and it is contemplated,therefore, by Y the appended claims, to cover any such modifications as:fall within the true spirit and scope of this invention.

We claim:

1. A hydraulic driving apparatus, comprising a housing provided with anelongated chamber, an apertured partition disposed in fixed relationwithin said chamber and forming a pair of contiguous compartments, anelon gated reciprocatory first element mounted for slidable engagementwithin the partition aperture, an elongated reciprocatory second elementdisposed Within one of said compartments and in aligned, continuousabutting relation with said first element, a movable unit operativelyconnected to said reciprocating elements for controlling the directionof movement thereof, and means carried by said first element andslidably cooperating with the aperture-forming portion of said partitionto effect auto matic movement of said unit upon reciprocation of saidelement.

2. A hydraulic driving apparatus comprising a housing provided with anelongated chamber, an apertured partition disposed in fixed relationwithin said chamber to form a pair of contiguous compartments, anelongated reciprocatory first element mounted for slidable engagementwithin the partition aperture, an elongated reciprocatory second elementdisposed within one of said compartments and in aligned, continuousabutting relation with said first element, a movable unit operativelyconnected to said reciprocating elements for controlling the directionof movement thereof, and means carried by said first element andslidably contacting the aperture-forming portion of said partition andcooperating therewith to form a passageway effecting intermittentindependent intercommunication of said compartments with said movableunit whereby movement of the latter is effected, said passageway beingformed only when said first element is in predetermined positions ofreciprocatory movement.

3. A hydraulic driving apparatus comprising a housing provided with anelongated chamber, a partition disposed in fixed relation within saidchamber to form a pair of compartments, said partition having a firstopening interconnecting said compartments and a second opening angularlydisposed with respect to said first opening and effecting communicationof said first opening with a port formed in said housing, an elongatedreciprocating first element occupying said partition first opening andeffecting isolating of one compartment from another, an elongatedreciprocatory second element disposed within one of said compartmentsand in aligned, continuous abutting relation with said first element,means for supplying hydraulic pressure to each compartment to effectactuation of said elements in opposite directions, and means carried onsaid first element and in slidable engagement.

with the portion of said partition defining said first opening toalternately effect communication of one of said compartments with saidsecond opening.

4. A hydraulic driving apparatus comprising a housing of hydraulicpressure,

hydraulically responsive elongated reciprocating element occupying saidpartition first opening and effecting isolating of one compartment fromthe other; a source of hy-.

draulic pressure; a reservoir for hydraulic fluid; a hydraulic pressureaccumulator communicting with said source and operatively connected tosaid first compartment and operable to act on the portion of saidelement disposed within said compartment and effect, at a predeterminedtime, movement of said element in one relative direction; a movablecontrol unit operatively connected to said source, said reservoir, saidsecond compartment and said housing port; and means carried by saidelement and slidably cooperating with said partition first opening toalternately efiect communication of each compartment with said secondopening; said control unit,.

when said element means effects communication between said firstcompartment and said second opening, being in one position of movementand responsive to said accumulator pressure and eflectinginterconnection of said source and said second compartment whereby theportion of said element, disposed within said second compartment isacted upon by said hydraulic pressure and said element is actuated in asecond relative direction; said control unit, when said element meanseffects communication between ing, assuming a second position ofmovement whereby said element is actuated in said one direction by saidaccumulator pressure and said reservoir and said second compartment areinterconnected.

5. The apparatus recited in claim 4, wherein the means carried by saidelement comprises a pair of longitudinally spaced elongated ways formedin the periphery of said element, one of said ways cooperating with theportion of said partition first, opening intermediate said firstcompartment and said second opening and the other way alternatelycooperating with the portion of said partition first openingintermediate said second compartment and said second opening;cooperation of said ways with said partition first opening portionsbeing dependent upon the positions of reciprocating adjustment of saidelement.

6. A hydraulic driving apparatus comprising a source a reservoir forhydraulic fluid, a housing provided with an elongated chamber, anapertured partition disposed within said chamber and forming contiguousfirst and second compartments, said first compartment being incontinuous communication with said source, a hydraulically responsivereciprocating element mounted for slidable engagement within thepartition aperture and effecting isolation of the first compartment fromthe second compartment, said element being formed of two separateabutting sections, one section being disposed wholly within said secondcompartment and the second section being disposed both in said first andsecond compartments, and a movable unit operatively connected to saidsource, said reservoir and said second compartment for controlling thedirection of movement of said element; said unit, when in one positionof movement, being responsive to said source of pressure and effectinginterconnection of said source and a portion of said element secondsection whereby said element sections are actuated as a unit in adirection toward one end of said chamber; said unit, when in a secondposition of movement, being out of communication with said source andeffecting interconnection of said reservoir and said element secondsection portion whereby said element sections are actuated as a unit ina direction toward the opposite end of said chamber.

7. The apparatus recited in claim 6 wherein said elesaid secondcompartment and said partition second open-- solders ment sections arein coaxial and continuing abutting relation, and movement of said unitis automatic.

8. The apparatus recited in claim 6, wherein the resultant force exertedon said element one section to effect actuation of said element sectionsas a unit in the direction toward said one end of said chamber is of agreater magnitude than the resultant force exerted on said elementsecond section to effect actuation of said element sections as a unit inthe direction toward said opposite end of said chamber.

9. The apparatus recited in claim 6, wherein said second element sectioncarries relatively spaced means, one means being operative to form afirst fluid communicating passageway between said first compartment andsaid movable unit, when said element sections are in one position ofreciprocation, and the second spaced means being operative to form asecond fluid communicating passageway between said movable unit and saidsecond compartment, when said element sections are in a second positionof reciprocation.

10. A hydraulic driving apparatus comprising a housing provided with anelongated chamber separated into two compartments by an aperturedpartition, said partition being provided with a first openinginterconnecting said compartments, and a second opening anguiarlydisposed with respect to said first opening and intermediate the endsthereof for effecting communication of said first opening with a portformed in said housing, a first source of hydraulic pressure incontinuous communication with one of said compartments, a second sourceof hydraulic pressure in intermittent communication with said secondcompartment, said first and second sources being in continuouscommunication with one another, a reservoir for hydraulic fluid inselective communication with said second compartment, a hydraulicallyresponsive reciprocating element formed of a pair of abutting elongatedsections, one section occupying said partition first opening and havinga portion thereof eontinuonslyaetedji position of reciprocatingadjustment, cooperating with" said partition first opening to form afluid passageway interconnecting said one compartment and said second;opening, and the other grooved segment, when said ele ment is in asecond position of reciprocating adjustment; cooperating with saidpartition first opening to form a fiuid passageway interconnecting saidsecondcompartment and said second opening.

11. The apparatus recited inclaim 1, wherein the elongated reciprocatoryfirst element is in continuous slidable engagement with the portion ofsaid partition defining an aperture thereof.

12. A hydraulic driving apparatus, comprising a housing provided with anelongated chamber, an apertured, partition disposed within said chamberand forming a pair of contiguous compartments, an elongatedreciprocatory element mounted for slidable engagement within thepartition aperture, a movable unit operatively connected to saidreciprocatory element for controlling the direction of movement of saidelement, and means carried by said ele ment comprising longitudinallyspaced ways formed in the periphery of said element slidably cooperatingwith the aperture-forming portion of said partition to etfect automaticmovement of said unit upon reciprocation of said element.

References Cited in the file ofthis patent" UNITED STATES PATENTS1,665,046 Tucker Apr. 3, 1928 1,771,238 Walsh July 22, 19 30 2,731,796Sublett et al Jan. 24, 6

